Tuesday, August 17, 2021

Never Water Your Fruit Trees Again?

I often get questions like, "How often should I water my fruit trees?" Fruit trees need lots of water to grow and produce fruit, but the amount of water needed really depends on where you live. Relative humidity, temperature, wind,  precipitation, slope, and soil type will all play a part in how often you water your trees. Too much water can cause problems like root rot and other soil born pathogens. Standing water on leaves can cause fungal diseases like powdery mildew.

How Often Should I Water My Fruit Trees?

There are complex calculations like the one below that can be used to determine the optimal watering schedule. These formulas take many of the above mentioned factors into play, but unless you like to geek out on Math and Physics, I would like to propose a much simpler solution that will not only help your trees get the water they need, but will also give your trees nutrients and reduce weed and pest pressure.

Evapotranspiration Rate Formula
Image used from: study.com

This year I watered my trees zero times. Yes, not even once and this was an unusually hot dry summer. At one point I was about to turn the water on, but a nice rain came just in time and did it for me. I understand that this is not always possible in every environment, but taking the guess work out of the complexities of watering your trees is possible.

Rain Dripping from Lemon Leaves

Because I prune trees and shrubs professionally, I'm able to chip and shred all of the leaves, branches, and other yard waste and spread it around my trees. The wood mulch is about 6 inches deep. When I move away the mulch I find a whole ecosystem of bugs, and fungi at the soil level and It stays surprisingly moist under there.

Wood Mulch Around Apple Trees

When snow melts in the spring the soil reaches field capacity and the mulch acts like a sponge and increases the amount of moisture in and around the tree. As spring turns to summer, the soil begins to dry, but the area around the tree is shaded and protected by the wood mulch. When the moisture in the mulch begins to evaporate, it keeps the soil underneath cool and moist. Eventually the soil will dry out, but every time it rains in the summer the sponge fills back up and the soil remains moist, but not too wet.

Orchard in the Snow

In addition to keeping the soil cool and moist, the mulch is constantly being broken down by bugs, worms, and fungi. As these organisms break down the mulch, they are releasing important nutrients that help feed the soil which ultimately feeds the tree. This doesn't happen all at once, but  slowly and consistently, just the way tree's like it.


Fungi Growing in Mulch

On occasion I will find a dandelion or orchard grass growing up through the mulch, but I just bury it with more mulch. Because of the complex ecosystem of beneficial insects and fungi, I don't worry about any one pest getting a strong hold and turning into an infestation.

A thick layer of wood mulch under your trees that extends out past the drip line of your tree, will help retain water, improve soil, feed your tree, and reduce weed and pest pressure. That all sounds pretty good right!?

How do you know if and when your tree needs water? Well, you just dig down to the soil and check. When the soil under the mulch feels dry, give your tree a long, slow soak. Longer, less frequent watering will decrease the amount of dissolved minerals in your soil and allow your trees to access the moisture they need.

If you enjoyed this article, please join our Backyard Fruit Growers Facebook Group and take our Free, Online Fruit Tree Pruning Course.